BEITUNIYA, West Bank {AP} Five Palestinian policemen manning a roadside checkpoint in the West Bank were killed by Israeli fire Monday, and Israeli helicopters rocketed Palestinian security targets in the Gaza Strip, destroying 10 armored vehicles.

Thousands of Palestinians chanting "revenge" gathered outside a West Bank hospital for a memorial procession for the policemen, who will eventually be buried near their homes in the Gaza Strip.

The officers, ages 17 to 29, were killed at a small Palestinian police outpost near the West Bank town of Beituniya, Palestinian officials said. Several bullets tore through the barrack walls.

Raanan Gissin, an adviser to Israeli Prime Minister Ariel Sharon, said shots were fired from the police station at Israeli soldiers, who returned fire. Gissin said he did not know whether the five men killed were the ones who opened fire. The Israeli army said the soldiers were engaged in an operation at the time and fired at "suspicious figures."

Two officers were the first killed, said Lt. Ahmed Hanoun, deputy commander of the Palestinian police. The others ran out when they heard the shots, and three more policeman were killed. A sixth was seriously wounded. Hanoun said he suspected snipers.

Across the Gaza Strip, Israeli helicopters and navy gunboats shelled 10 Palestinian security installations, including a compound of the Force 17 security service, a Palestinian police building and the offices of Palestinian leader Yasser Arafat's Fatah movement.

Four people were injured by shrapnel and one suffered from shock, doctors said.

Palestinian armored vehicles apparently were the main target of the raids. Ten were destroyed, the Palestinians said. The Israeli army put the figure at eight.

The army said the attacks came in retaliation for "continuous Palestinian terror and violent escalation in recent days."

Arafat denounced the Israeli attacks, calling the killing in Beituniya "assassinations" and a "dirty operation." He said the rocket attacks in Gaza were aimed at demoralizing his people, but "they cannot be shaken." He said Israel would pay for its crimes.

Also Monday, the Israeli army demolished a Palestinian police station and several other buildings in the West Bank village of Shuwakeh near the city of Tulkarem in an area under Israeli security control. The army said Palestinian policemen had used the station and the buildings to fire at Israeli troops.

Palestinian officials said the buildings were part of the Khadoury Agricultural College in Palestinian territory. Adnan Abu Islaih, dean of the college, said cow sheds belonging to the school were destroyed.

In operations condemned by the United States, Israeli forces have frequently entered Palestinian-controlled territory in recent weeks in response to Palestinian gunfire and mortar attacks.

Also Monday, police defused an explosive discovered near a bus station in the central Israeli city of Petah Tikvah.

Late Sunday, Sharon met with senior ministers to discuss proposals to end the violence that has killed 446 people on the Palestinian side and 77 on the Israeli side.

Israel is expected to form its official response within days. The international Mitchell Commission report asks both sides to halt violence, and calls on Israel to stop construction in Jewish settlements in the West Bank and Gaza.

Sharon told visiting Canadian Foreign Minister John Manley on Sunday that earlier, partial peace accords stipulate that the fate of settlements will only be determined in a final peace deal. Stopping construction would "reward" Palestinian violence, he said.

Sharon has also criticized an Egyptian-Jordanian plan for the resumption of peace talks that calls on Israel to halt building in the settlements.

The Palestinians have accepted both plans. Arafat's deputy, Mahmoud Abbas, is to meet with Secretary of State Colin Powell this week, according to Hassan Abdel Rahman, the Palestinian representative in Washington.